Cutting tool

Abstract

A cutting tool comprises a substrate and a coating film disposed on the substrate, wherein the coating film comprises a first layer and a second layer; the first layer has a hardness H1 of 25 GPa or more and 40 GPa or less; the second layer has a hardness H2 satisfying 0.5×H1≤H2≤0.9×H1; and at least one of a ratio I(200)/(I(200)+I(111)+I(220)) of I(200) of (200) plane to a sum of X-ray diffraction intensity I(200) of (200) plane, X-ray diffraction intensity I(111) of (111) plane, and X-ray diffraction intensity I(220) of (220) plane of the coating film, a ratio I(111)/(I(200)+I(111)+I(220)) of I(111) to the sum, and a ratio I(220/(I(200)+I(111)+I(220)) of I(220) to the sum is 0.45 or more.

The invention claimed is: 
     
       1. A cutting tool comprising a substrate and a coating film disposed on the substrate, wherein
 the coating film comprises a first layer and a second layer: 
 the first layer has a hardness H 1  of 25 GPa or more and 40 GPa or less: 
 the second layer has a hardness H 2  satisfying 0.5×H 1≤ H 2 ≤0.9×H 1 ; 
 at least one of a ratio I (200) /(I (200) +I (111) +I (220) ) of I (200)  of (200) plane to a sum of X-ray diffraction intensity I (200)  of (200) plane, X-ray diffraction intensity I (111)  of (111) plane, and X-ray diffraction intensity I (220)  of (220) plane of the coating film, a ratio I (111) /(I (200) +I (111) +I (220) ) of I (111)  to the sum, and a ratio I (220) /(I (200) +I (111) +I (220) ) of I (220)  to the sum is 0.45 or more; 
 the first layer consists of a first unit layer and a second unit layer; 
 the first unit layer is composed of Ti x Al y M 1-x-y C z N 1-z ; 
 M is one element selected from the group consisting of zirconium, hafnium, group V elements and group VI elements of the periodic table, silicon, boron, and yttrium; 
 x is 0.20 or more and 0.99 or less, 
 y is 0.01 or more and 0.80 or less, 
 1-x-y is 0.01 or more and 0.20 or less, and 
 z is 0 or more and 1.0 or less; 
 the second unit layer is composed of Al m Cr 1-m N; 
 m is 0 or more and 0.8 or less, 
 the first unit layer has a thickness of 5 nm or more and 50 nm or less, 
 the second unit layer has a thickness of 5 nm or more and 50 nm or less, and 
 the first unit layer is in contact with the second unit layer and the first unit layer and the second unit layer are alternately laminated. 
 
     
     
       2. The cutting tool according to  claim 1 , wherein the first layer has a thickness T 1  of 0.2 μm or more and 10 μm or less. 
     
     
       3. The cutting tool according to  claim 1 , wherein the second layer has a thickness T 2  of 0.2 μm or more and 10 μm or less. 
     
     
       4. The cutting tool according to  claim 1 , wherein a ratio T 1 /T 2  of thickness T 1  of the first layer to thickness T 2  of the second layer is 0.02 or more and 50 or less. 
     
     
       5. The cutting tool according to  claim 1 ,
 wherein the second layer comprises a fourth unit layer; 
 the fourth unit layer is composed of Ti a Al b C c N 1-c ; 
 a is 0.2 or more and 1.0 or less, 
 b is 0 or more and 0.8 or less, and 
 c is 0 or more and 1.0 or less. 
 
     
     
       6. The cutting tool according to  claim 5 , wherein b and c are both greater than 0. 
     
     
       7. The cutting tool according to  claim 1 , wherein M is one element selected from the group consisting of zirconium, hafnium, group V elements and group VI elements of the periodic table, boron, and yttrium. 
     
     
       8. The cutting tool according to  claim 1 , wherein z is more than 0 and 1.0 or less. 
     
     
       9. A cutting tool comprising a substrate and a coating film disposed on the substrate, wherein
 the coating film comprises a first layer and a second layer: 
 the first layer has a hardness H 1  of 25 GPa or more and 40 GPa or less: 
 the second layer has a hardness H 2  satisfying 0.5×H 1 ≤H 2 ≤0.9×H 1 ; 
 at least one of a ratio I (200) /(I (200) +I (111) +I (220) ) of I (200)  of (200) plane to a sum of X-ray diffraction intensity I (200)  of (200) plane, X-ray diffraction intensity I (111)  of (111) plane, and X-ray diffraction intensity I (220)  of (220) plane of the coating film, a ratio I (111) /(I (200) +I (111) +I (220) ) of I (111)  to the sum, and a ratio I (220) /(I (200) +I (111) +I (220) ) of I (220)  to the sum is 0.45 or more; 
 the first layer consists of a first unit layer and a third unit layer; 
 the first unit layer is composed of Ti x Al y M 1-x-y C z N 1-z ; 
 M is one element selected from the group consisting of zirconium, hafnium, group V elements and group VI elements of the periodic table, silicon, boron, and yttrium; 
 x is 0.20 or more and 0.99 or less, 
 y is 0.01 or more and 0.80 or less, 
 1-x-y is 0.01 or more and 0.20 or less, and 
 z is 0 or more and 1.0 or less; 
 the third unit layer is composed of Ti 1-n Al n N; 
 n is 0 or more and 0.8 or less, 
 the thickness of the first unit layer is 5 nm or more and 50 nm or less, 
 the thickness of the third unit layer is 5 nm or more and 50 nm or less, and 
 the first unit layer is in contact with the third unit layer and the first unit layer and the third unit layer are alternately laminated. 
 
     
     
       10. The cutting tool according to  claim 9 , wherein the first layer has a thickness T 1  of 0.2 μm or more and 10 μm or less. 
     
     
       11. The cutting tool according to  claim 9 , wherein the third layer has a thickness T 2  of 0.2 μm or more and 10 μm or less. 
     
     
       12. The cutting tool according to  claim 9 , wherein a ratio T 1 /T 2  of thickness T 1  of the first layer to thickness T 2  of the second layer is 0.02 or more and 50 or less. 
     
     
       13. The cutting tool according to  claim 9 ,
 wherein the third layer comprises a fourth unit layer; 
 the fourth unit layer is composed of Ti a Al b C c N 1-c ; 
 a is 0.2 or more and 1.0 or less, 
 b is 0 or more and 0.8 or less, and 
 c is 0 or more and 1.0 or less. 
 
     
     
       14. The cutting tool according to  claim 13 , wherein b and c are both greater than 0. 
     
     
       15. The cutting tool according to  claim 9 , wherein M is one element selected from the group consisting of zirconium, hafnium, group V elements and group VI elements of the periodic table, boron, and yttrium. 
     
     
       16. The cutting tool according to  claim 9 , wherein z is more than 0 and 1.0 or less.